A window screen typically involves a sheet of mesh material, often moulded from a flexible plastics material, a frame and means for affixing the mesh material to the frame. The affixing means usually involves a bead of flexible retaining material which is forced into a groove in the face of the frame along with the screen material. The flexible material exerts an outward pressure on the screen material to hold it securely in the groove.
When it becomes necessary to repair the screen, the bead is pulled from the groove and the screen material is lifted from the frame. New screen material is laid over the frame, pushed into the groove with a tool and then a new bead is forced into the groove by using another tool so as to stretch the screen material and to affix it to the frame.
In the past the tool used to affix the bead to the groove, or to initially push the screen material into the groove, has included a straight handle and a thin circular roller wheel. As the tool is moved along the groove the wheel rotates and with sufficient downward pressure it will force the screen material or the bead and screen material into the groove. A tool for just pushing screen material into the groove can have a transversely rounded edge and the tool for pushing the bead into the groove can have a transversely V-shaped edge.
Such a tool has two major drawbacks. It is expensive to manufacture, comprising several components, and it cannot reach into the corners where grooves of abutting frame members meet. This latter problem has necessitated the use of other tools, such as screwdrivers to ensure proper assembly at the corners.